JP2007127797A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module, wherein a plurality of optical signals can be transmitted and received without deterioration and an LD and a PD can be arranged at desired positions. <P>SOLUTION: The optical module is provided with: an optical waveguide array 12 having a plurality of optical transmission lines 11; a photoelectric element array 14 having a plurality of photoelectric elements 13; and a lens component 15 which is interposed between the photoelectric element array 14 and the optical waveguide array 12, and has: a first convex lens 16 which is arranged opposite to the optical waveguide array 12 and has an effective diameter larger than the distance between the optical axes of the mutually most-distant two optical transmission lines 11 of the optical waveguide array 12; and a second convex lens 17 which is arrange opposite to the photoelectric array 14 and has an effective diameter larger than the distance between the optical axes of the mutually most-distant two photoelectric elements 13 of the photoelectric element array 14. The first convex lens 16 is formed so as to change optical signals from each optical transmission line 11 to parallel light, and the second convex lens 17 is formed so that the optical signals are converged through the lens component 15 on each photoelectric element 13, and the parallel light of each optical signal passing through the lens component 15 is crossed nearly at one place. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical module for transmitting, receiving, or transmitting / receiving a plurality of optical signals.

  At the end of the optical communication system, an optical module that transmits an optical signal converted from an electrical signal to an optical transmission path such as an optical fiber, and an optical module that receives an optical signal from optical transmission are used. An optical module mounted with a PD array or an LD array is used to transmit or receive an optical signal.

  FIG. 15 is a plan view for explaining an optical module for reception in which optical signals from a plurality of optical fibers are received by a plurality of light receiving elements (for example, photodiodes: PD).

  As shown in FIG. 15, the optical module 120 includes an optical fiber group 122 having a plurality of optical fibers 121 and a plurality of light receiving elements (PD) 123 that respectively receive optical signals from the fibers 121 of the optical fiber group 122. The PD array 124, and the PD array 124 and the optical fiber group 122. The optical signals are individually guided between the optical fibers 121 of the optical fiber group 122 and the PDs 123 of the PD array 124. And a lens component 125. The lens component 125 includes a plurality of optical fiber side convex lenses 126 and a plurality of PD side convex lenses 127, which are arranged in parallel.

  The optical signal emitted from each optical fiber 121 is collimated by the fiber-side convex lens 126, and the collimated light (parallel light) is collected by the PD-side convex lens 127 and received by each PD 123 at a substantially focal position. In this optical module, a set of convex lenses (microlenses) is provided for each optical fiber and corresponding PD, so that optical signals from the optical fiber 121 can be individually coupled to the PD 123.

  In addition, as the technical literature information of the optical module having the configuration as shown in FIG.

JP 2005-31556 A

  The lens component 125 mounted on the conventional optical module 120 collimates a plurality of optical signals by arranging a plurality of microlenses in parallel. For example, the interval between the PDs 123 of the PD array 124 is small. For reasons such as prescribed, when the distance (pitch) between the optical fibers 121 and the distance between the PDs 123 are small, the diameter (effective diameter or aperture) of the convex lens has to be reduced. The optical fiber 121 has a predetermined NA (numerical aperture), and the emitted light (signal light) is emitted with a predetermined divergence angle. Therefore, in order to make the outgoing light of the optical fiber 121 enter the lens with a small diameter without fail (to make the outgoing light enter while the beam diameter of the outgoing light is smaller than the lens diameter), the lens component 125 is made of the LD or PD 123 of the PD side lens 127. It must be installed in the immediate vicinity.

  However, some LD packages and PD packages including LDs and PDs have a problem that they cannot be disposed within the focal length of the lens for structural reasons. That is, there is a problem that the LD or PD cannot be disposed at a desired position in the optical module regardless of the structure of the LD package or PD package.

  In general, when a small amount of dust or dirt (contamination, contamination) adheres to the convex lens, the optical signal transmitted through the lens deteriorates. In the conventional optical module 120, since the diameter of the convex lens is small, the size ratio of the contamination to the lens diameter (optical signal diameter) is large. Therefore, there is a problem that the contamination attached to the lens surface deteriorates the optical signal.

  In addition, as shown in FIG. 16, when concentrating a plurality of optical signals (for example, four) on a plurality of optical fibers 132 arranged at a predetermined interval, the diameter is such that the plurality of optical signals can be incident. When incident on one lens 131, the optical axes of the optical signals emitted from the lens 131 are not parallel to each other, but are incident obliquely on a plurality of optical fibers 132 arranged in parallel, resulting in coupling loss. Resulting in.

  Accordingly, an object of the present invention is to provide an optical module that solves the above-described problems, can transmit / receive a plurality of optical signals without degrading, and can dispose an LD or PD at a desired position in the optical module. It is in.

  In order to achieve the above object, the invention of claim 1 is directed to an optical waveguide group having a plurality of optical transmission lines, and to receive an optical signal from each optical transmission line of the optical waveguide group, or to each optical transmission. A photoelectric element group having a plurality of photoelectric elements that transmit optical signals to the path, and interposed between the photoelectric element group and the optical waveguide group, each optical transmission path of the waveguide body group and the photoelectric element group An optical module including a lens component for individually transmitting or receiving an optical signal to or from each of the photoelectric elements, wherein the lens component is disposed to face the optical waveguide group. A first convex lens having an effective diameter larger than the distance between the optical axes of the two optical transmission lines farthest from each other in the group, and 2 which are arranged opposite to the photoelectric element group and which are farthest from each other in the photoelectric element group Has an effective diameter larger than the distance between the optical axes of two photoelectric elements A second convex lens, and the first convex lens condenses the optical signal from each optical transmission path of the optical waveguide group into parallel light or condenses the optical signal that has passed through the lens component on each optical transmission path. The second convex lens is formed so that the optical signal from each photoelectric element of the photoelectric element group becomes parallel light, or the optical signal that has passed through the lens component is condensed on each photoelectric element. And an optical module formed so that parallel light of each optical signal passing through the lens component intersects at substantially one location.

  According to a third aspect of the present invention, the lens component is formed of a substantially rectangular parallelepiped lens block, the first convex lens is formed on one side of the lens block, and the second convex lens is opposed to the side on which the first convex lens is formed. The optical module according to claim 1, wherein the optical module is formed on a side to be connected.

  According to a fourth aspect of the present invention, the lens component is formed of a substantially rectangular parallelepiped lens block, the first convex lens is on one side of the lens block, and the second convex lens is orthogonal to the side on which the first convex lens is formed. 2. The optical module according to claim 1, wherein the optical module is formed on the block side, and a mirror that couples the optical axis of the first convex lens and the optical axis of the second lens is formed in the lens block.

  According to a fifth aspect of the present invention, the lens block is formed in a substantially rectangular parallelepiped, a pair of first convex lenses are formed on one side of the rectangular parallelepiped, and a second convex lens is formed on a side of the first convex lens facing the rectangular parallelepiped side. The optical module according to claim 1, wherein the second convex lens is formed on the rectangular parallelepiped side perpendicular to the other first convex lens, and a mirror is formed therebetween.

  According to a sixth aspect of the present invention, in the lens block, a hollow hole for forming the mirror is formed at a position where the optical axis of the first convex lens and the optical axis of the second convex lens are coupled. 5. The optical module according to 5.

  According to a seventh aspect of the present invention, the lens component forms a substantially rectangular parallelepiped lens block with the same material as that for forming the first convex lens and the second convex lens, and is substantially the same as the first convex lens on one side thereof. A concave portion having the same diameter is formed, a first convex lens is formed in the concave portion, a concave portion having substantially the same diameter as the second convex lens is formed on the other side surface of the lens block, and a second convex lens is formed in the concave portion. It is an optical module in any one of Claims 3-6.

  According to an eighth aspect of the present invention, a fitting projection or a fitting groove for positioning and fitting with an external component such as an optical connector is formed on the surface of the lens block on which the first convex lens or the second convex lens is formed. 8. The optical module according to claim 3, wherein the concave portion is formed at a depth at which a focal point of the second convex lens is located on an opening surface of the concave portion.

  A ninth aspect of the invention is the optical module according to any one of the first to eighth aspects, wherein a focal length of the first convex lens is different from a focal length of the second convex lens.

  The invention according to claim 10 is the optical module according to any one of claims 1 to 9, wherein the optical waveguide group is a plurality of optical fibers arranged one-dimensionally or two-dimensionally.

  The invention according to claim 11 is the optical module according to any one of claims 1 to 10, wherein the photoelectric element group is a plurality of light receiving elements or light emitting elements arranged one-dimensionally or two-dimensionally.

  According to a twelfth aspect of the present invention, the photoelectric element group is provided on a substrate, a cap having an optically transparent window formed above the photoelectric element group is fixed to the substrate, and the photoelectric element group is hermetically sealed. The optical module according to claim 11 stopped.

  According to the present invention, it is possible to transmit and receive a plurality of optical signals without degrading them, and to exhibit an excellent effect that LDs and PDs can be arranged at desired positions in an optical module.

  Hereinafter, a preferred first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the optical module according to the present embodiment includes an optical waveguide group 12 having a plurality of optical transmission paths 11 and optical signals L1 to L4 from the optical transmission paths 11 of the optical waveguide group 12. A photoelectric element group 14 having a plurality of photoelectric elements 13 to be respectively received, and a lens component 15 for individually transmitting or receiving optical signals L1 to L4 between the photoelectric element group 14 and the optical waveguide group 12 are provided. I have.

  The plurality of optical transmission lines 11 are arranged in a line so that the optical axes of the respective optical transmission lines 11 are parallel to each other. An optical fiber is used as the optical transmission line 11, and an optical fiber array or a planar optical waveguide element is used as the optical waveguide group. The photoelectric element group 14 includes a plurality of photoelectric elements 13 arranged in a line such that the light receiving surfaces thereof face in the same direction (the optical axes of the light receiving surfaces are parallel), and a photodiode array (PD array). ). Examples of the photoelectric element 13 include a light receiving element that receives an optical signal. The light receiving element 13 is preferably a photodiode. In this embodiment, four optical transmission lines 11 and four photoelectric elements 13 are provided in order to receive four-channel optical signals.

  The lens component 15 includes a first convex lens 16 and a second convex lens 17. The first convex lens 16 is disposed so as to face the optical waveguide group 12 and has an effective diameter larger than the distance between the optical axes of the two optical transmission lines 11 and 11 farthest from the optical waveguide group 12. The second convex lens 17 is disposed to face the photoelectric element group 12 and has an effective diameter larger than the distance between the optical axes of the photoelectric elements 13 and 13 that are farthest from the optical waveguide group 12.

  In the present embodiment, the first convex lens 16 and the second convex lens 17 are formed identically. That is, the lens diameter (effective diameter), the curvature, and the material forming the lens (refractive index) are the same. Further, the first convex lens 16 and the second convex lens 17 are arranged to face each other.

  The first convex lens 16 has an aspheric lens surface 18 on the optical waveguide group 12 side, and the second convex lens 17 has an aspheric lens surface 18 on the photoelectric element group 14 side. The first convex lens 16 and the second convex lens 17 are each formed on the plane 19 on the side facing the other convex lens. In the present embodiment, the lens surface 18 is formed as an aspherical surface, but may be formed as a spherical lens. Moreover, although the mutually opposing surface of the 1st convex lens 16 and the 2nd convex lens 17 was formed in the plane 19 in this Embodiment, any shape, such as a concave surface and a convex surface, may be sufficient.

  Further, the first convex lens 16 and the second convex lens 17 are formed and arranged to propagate a plurality of optical signals L1 to L4 through an optical path as described below.

  The optical signals L1 to L4 emitted from the respective optical transmission lines 11 are incident on the first convex lens 16 while expanding their diameters (beam diameters). The optical signals L1 to L4 are refracted at the lens surface 18 and the plane 19, and the optical signals L1 to L4 emitted from the first convex lens 16 are converted into parallel light while the optical axis (principal ray) is bent. Heading toward the convex lens 17. At this time, the optical signals L1 to L4 have a larger optical axis bending angle (propagation angle) as the optical signal is incident on the first convex lens 16, and the smaller the optical axis bending angle, the closer to the center. Therefore, the plurality of optical signals L1 to L4 that have exited from the first convex lens 16 and became parallel light respectively intersect at approximately one place (C1 in the figure).

  In the second convex lens 17, the optical axes of the parallel lights collimated by the first convex lens 16 are made parallel to each other, and each parallel light is condensed on each photoelectric element 13.

  In FIG. 1, the optical module in which the photoelectric element 13 is a light receiving element and the light emitted from the optical fiber is received by the light receiving element has been described. However, the light emitting element is used as the photoelectric element 13 and the light emitted from the light emitting element is the optical fiber. You may make it enter into. The light emitting element is preferably a laser diode (LD), and the photoelectric element group 14 includes a diode array (LD array). At that time, the plurality of optical signals emitted from the photoelectric elements only have their propagation directions opposite to the propagation directions of the optical signals shown in FIG. 1, and the other operations are the same.

  According to the optical module 10 of the present embodiment, when a plurality of optical signals are individually propagated, a convex lens having a diameter (effective diameter) larger than the distance between the optical axes of the optical transmission lines 11 that are farthest from each other is used. Therefore, even if the distance between the lens component 15 and the optical waveguide group 12 is made longer than that of the conventional optical module, the optical signal emitted from each optical transmission line 11 and expanded at a predetermined divergence angle is completely transmitted to the lens component 15. It can be made incident.

  Accordingly, the focal length of the light incident on or emitted from the lens component 15 can be increased as compared with the conventional lens component without losing the optical signal, so that the photoelectric element group 14 and the optical waveguide The group 12 can be optically connected to the lens component 15 at a desired position. For example, since the structure and size of the photoelectric element group 14 are defined (standards are determined), an LD array or a PD array that cannot be connected unless the distance from the lens component 15 is equal to or longer than a predetermined length. An optical module in which such an LD array or PD array is integrally connected to the lens component 15 can be realized.

  As another example, an optical element such as a cap (see a fifth embodiment described later) or an isolator for preventing airtightness can be inserted between the photoelectric element group and the convex lens.

  In addition, since the lens component 15 can emit the optical axes of the optical signals L1 to L4 in parallel with each other, the light emitting element is used as the photoelectric element 13, and the light emitted from the light emitting element is incident on the optical fiber. The optical fibers can be received by each optical fiber without deteriorating the optical characteristics (particularly, light intensity) of the optical signal.

  Further, in the optical module 10, the diameters of the first convex lens 16 and the second convex lens 17 of the lens component 15 are made larger than those of the conventional convex lenses 126 and 127 (see FIG. 15) of the optical module 120, and the optical waveguide group. 12, the distance between the photoelectric element group 14 and the lens component 15 is increased, and the optical signal is enlarged and incident on the lens component 15, so that the adverse effect of contamination on the lens surface 18 on the optical signal is reduced. be able to.

  Next, an optical module according to a preferred second embodiment will be described.

  As shown in FIG. 2, in the optical module 20 of the present embodiment, a lens component 21 is formed in a columnar shape, a first convex lens 16 is formed at one end of the columnar body, and a second convex lens 17 is formed at the other end. Is formed.

  That is, the lens component 21 is formed of the same material so that the first convex lens 16 and the second convex lens 17 are integrated via the inter-lens component 22. In the optical module 10 of FIG. 1, the medium between the first convex lens 16 and the second convex lens 17 is air, whereas in the optical module 20 of the present embodiment, the distance between the first convex lens 16 and the second convex lens 17 is the same. These biconvex lenses 16 and 17 are different in that they are formed of a medium having the same refractive index.

  In the lens component 21, a plurality of optical signals become parallel light and intersect at substantially one place as in the optical module of FIG. 1. However, since there is no refractive index boundary in the lens component 21, the refractive change does not occur on the plane 19 as shown in FIG.

Since the first convex lens 16 and the second convex lens 17 are formed integrally with the lens component 21, there is an advantage that once the lens component 21 is formed, it is not necessary to adjust the optical axis between the lenses.
Next, an optical module according to a preferred third embodiment will be described.

  As shown in FIG. 3, in the present embodiment, the lens component 30 includes a first convex lens 16, a second convex lens 17, and a substantially rectangular parallelepiped lens block 31, and a first convex lens on one surface 32 of the lens block 31. 16 is formed, and the second convex lens 17 is formed on the surface 33 of the lens block 31 facing the surface 32 on which the first convex lens 16 is formed.

  Specifically, a cylindrical concave portion 34 substantially equal to the lens diameter of the first convex lens 16 is formed on one surface 32 of the lens block, and the first convex lens 16 is provided on the bottom surface of the concave portion 34. Similarly, a concave portion 35 having the same shape is formed on the surface 33 of the facing lens block 31, and the second convex lens 17 is formed on the bottom surface of the concave portion 35. The first convex lens 16, the second convex lens 17 and the lens block 31 are integrally formed of the same material, and the space between the first convex lens 16 and the second convex lens 17 is also enriched with the material forming the lens block 31. In the present embodiment, the lens component 30 is molded from resin. As described above, in the optical module according to the present embodiment, the lens component 30 is equivalent to the lens component 21 shown in FIG. 2 in the propagation of the optical signal, and has the same effect as the optical module 20 of FIG.

  Further, as shown in FIG. 4, a fitting protrusion 41 (in the drawing, for positioning and fitting with an external component such as an optical connector to which an optical fiber is connected is provided on the surface 32 on which the first convex lens 16 is formed. 2) may be formed. As shown in FIG. 1, the first convex lens 16 is focused on an optical waveguide group 12 such as an optical fiber array. When the fitting groove is formed on the end face of the optical connector to which the optical fiber is connected, the fitting projection 41 is positioned so that the emission end face of the optical connector is positioned at a position where a plurality of optical signals are collected. Is formed. At the same time, the depth d of the recess 34 is also adjusted. Specifically, as shown in FIG. 5, the depth d of the concave portion 34 is adjusted so that the focal position F of the first convex lens 16 is positioned on the opening surface 43 of the concave portion 34. Thereby, the focal point of the first convex lens 16 is positioned on the end surface of the optical fiber 11 accommodated in the optical connector 42 only by bringing the optical connector 42 into contact with the surface 32 of the lens block 31. Therefore, the optical axis of each optical signal can be obtained by simply fitting the fitting protrusion 41 (see FIG. 4) of the lens component 40 into the fitting groove (not shown) of the optical connector 42, without performing alignment work. The lens component 40 can be connected to the optical connector so as to coincide with each optical transmission path of the optical connector.

  The fitting protrusion 41 may be formed on the lens block surface 33 on which the second convex lens 17 is formed, or may be formed on both surfaces 32 and 33 of the lens block 31. Further, when a fitting protrusion is formed on an external component such as a connector, a fitting groove may be formed instead of the fitting protrusion 41.

  Next, an optical module according to a preferred fourth embodiment will be described.

  As shown in FIGS. 6A and 6B, in the optical module according to the present embodiment, the lens component 60 includes a lens block 61 formed in a substantially rectangular parallelepiped. A first convex lens 16 is formed, a second convex lens is formed on the surface 63 of the lens block 61 orthogonal to the surface 62 on which one of the first convex lenses 16 is formed, and a mirror 64 (mirror surface) is formed therebetween. ing.

  Specifically, a hollow hole 65 for forming a mirror surface 64 is formed in the lens block 61 at a position where the optical axis of the first convex lens 16 and the optical axis of the second convex lens 17 are coupled. In the lens component 60, the optical axis of the first convex lens 16 and the optical axis of the second convex lens 17 are orthogonal to each other, and the mirror surface 64 is formed with an inclination of about 45 ° with respect to both optical axes. Regarding the depth of the hollow hole 65, when the hollow hole 65 is formed from above the lens block 61, the bottom surface 65a of the hollow hole 65 may be positioned below the first convex lens (second convex lens).

  FIG. 7 is a plan view for explaining propagation of an optical signal of the optical module including the lens component 60 shown in FIG.

  As shown in FIG. 7, in the optical module 50, the plurality of optical signals emitted from the optical waveguide group 12 expand the diameter of each optical signal while keeping the optical axes parallel to each other, and the first convex lens 16. Is incident on. In the first convex lens 16, each optical signal becomes parallel light, and the optical axes of the plurality of optical signals are collected. The plurality of optical signals that are each parallel light is reflected by the mirror 64 and travels toward the second convex lens. In the second convex lens 17, the optical axes of a plurality of optical signals are made parallel, and each optical signal is condensed on the photoelectric element 13.

  In the present embodiment, mirrors 64 are provided at positions where a plurality of optical signals that have become parallel lights intersect at substantially one place (in the figure, C2), but the mirrors 64 have become parallel lights. It may be provided at a position where the optical signals are reflected before the plurality of optical signals intersect, or may be provided at a position where the optical signals are reflected after the plurality of optical signals intersect.

  Next, an optical module according to a preferred fifth embodiment will be described.

  As shown in FIG. 8, in the optical module of the present embodiment, the lens component 70 includes a substantially rectangular parallelepiped lens block 71, two first convex lenses 16a and 16b, and two second convex lenses 17a and 17b. A pair of first convex lenses 16a and 16b are formed on one side surface 72 of the lens block 71, and one second convex lens 17a is formed on a surface 73 opposite to the surface 72 on which the first convex lens 16a is formed. The other second convex lens 17b is formed on the surface 75 of the lens block 71 orthogonal to the other first convex lens 16b, and the optical axis of the other first convex lens 17a and the optical axis of the other second convex lens 17b A mirror 64 that is reflected so as to be coupled to each other is formed. In the mirror 64, a hollow hole 65 for forming the mirror surface 64 is formed at a position where the optical axis of the first convex lens 16b and the optical axis of the second convex lens 17b are orthogonal to each other.

  That is, the lens component 70 according to the present embodiment includes the lens component 40 shown in FIG. 4 and the lens component 60 shown in FIG. This is almost the same as that in which the pair of first convex lenses 16a and 16b are formed in the concave portion 74.

  In the optical module according to the present embodiment, for example, a plurality of transmission optical fibers (not shown) are connected to one first convex lens 16a as a transmission optical waveguide, and a reception optical is connected to the other first convex lens 16b. A plurality of receiving optical fibers not shown as wave bodies are connected, an LD array not shown as a transmitting photoelectric element group (light emitting element group) is provided on one second convex lens 17a side, and the other second convex lens 17b side is provided. A PD array (not shown) is provided as a receiving photoelectric element group (light receiving element group).

  In the optical module of the present embodiment, the optical signals (L1s, L4s) emitted from the light emitting element group propagate to the opposing optical waveguide group via the lens component 70, and from the optical waveguide group for reception. Optical signals (L1r, L4r) are reflected by the mirror 64 in the lens component 70 and received by the light receiving element group.

  An optical module using the lens component 70 of FIG. 8 will be described.

  As shown in FIGS. 9A to 9D, the optical module 80 includes a CAN type PD 82 that is a photoelectric element group for reception and a transmission type in a lens housing portion 81 that houses the lens component 70 of FIG. And a CAN type LD 83, which is a photoelectric element group, and is optically connected to the lens component 70. The CAN-type PD 82 is provided on the side facing the second convex lens 17b of FIG. 8, and the CAN-type LD 83 is provided on the side facing the second convex lens 17a of FIG. The optical module 80 is a light in which a multi-core connector to which a transmission and reception optical waveguide group is connected is inserted on the side of the lens component 70 facing the pair of first convex lenses 16a and 16b (see FIG. 8). A transceiver case 84 is integrally provided. Reference numeral 85 denotes an insertion slot for inserting a multicore connector, and 86 denotes a locking member for fixing the inserted multicore connector in the optical transceiver case 84.

  As shown in FIG. 10A, the CAN type PD 82 is obtained by mounting the PD array 14 on a CAN package 87. In the CAN package 87, related circuit elements (not shown) connected to the PD array 14 are disposed on a disk-shaped substrate 88, and the substrate 88 is electrically connected to the PD array 14 and related circuit elements. The CAN package body 90 is provided with an input / output pin 89 that penetrates and extends to the back surface of the substrate, and a cap 91 for hermetically sealing the PD array 14. As shown in FIG. 10 (b), the cap 91 is formed of a glass window 92 whose upper surface is optically transparent (transmits an optical signal), covers the PD array 14 provided on the substrate 88, and has a PD. A space in which the array 14 is accommodated is formed in an airtight manner. In order to maintain the high airtightness of the PD array 14, the cap 91 is preferably fixed to the substrate 88 by welding with solder, low melting point glass, silver brazing, or the like.

  However, in order to mount the CAN type PD 82 on the optical module 80, the distance between the PD array 14 and the second convex lens 17 must be larger than the sum of the thickness w of the glass window 92 and the height h of the bonding wire 93. .

  In the conventional optical module, the focal length of the convex lens is shorter than the height of the peripheral wall of the cap that covers the periphery of the PD array 14 (the sum of the thickness w of the glass window 92 and the height h of the bonding wire 93). The CAN type PD82 could not be mounted.

  However, as described in FIG. 8, the optical module 80 according to the present embodiment includes the lens component 70 provided with the second convex lens in which the effective diameter and the radius of curvature are increased to increase the focal length. As a result, the focal length of the second convex lens 17b can reach the PD array 14 in the CAN package 87, so that the CAN-type PD 82 can be mounted.

  Therefore, the optical module 80 of the present embodiment can be mounted with a CAN type PD 82 (CAN type LD 83) having a structure in which the PD array 14 (LD array) is hermetically sealed. The reliability and durability of the photoelectric element can be improved without moisture or the like entering.

  Further, the CAN package 87 is inexpensive, and the CAN type package 87 can be used, so that the cost of the optical module can be reduced.

  In addition, instead of the CAN package 87, a ceramic package provided with a glass cap for hermetic sealing may be used. For example, a ceramic package 94 shown in FIG. 11 is generally used for manufacturing an electric module by mounting a crystal oscillator or the like. The ceramic package 94 is provided with an electric wiring pattern 96 on a substrate 95 made of ceramic, and a seam ring 97 along the periphery of the substrate 95. A glass window (not shown) is formed on the upper surface of the seam ring 97. As a result, the seam ring 97 and the glass window hermetically seal the photoelectric element group disposed on the substrate 95 in the same manner as the cap 91 described above.

  In the first to fifth embodiments, the first convex lens 16 and the second convex lens 17 are formed the same, but the curvature of the lens surface 18 of the first convex lens 16 and the curvature of the lens surface 18 of the second convex lens 17 are calculated. They may be formed differently from each other.

  As shown in FIG. 12, the lens component 101 is formed such that the curvature of the second convex lens 103 is larger than the curvature of the first convex lens 102. Thereby, the focal length of the second convex lens 103 can be made longer than the focal length of the first convex lens 102. Therefore, the distance between the lens component 101 and the optical waveguide group 12 (focal length of the first convex lens 102) and the distance between the lens component 101 and the photoelectric element group 14 (focal length of the second convex lens 103) are different. The optical waveguide group 12 and the photoelectric element group 14 can be mounted.

  Further, in the lens component 101, the focal distance (pitch) S2 on the second convex lens 103 side of each optical signal can be made larger than the focal distance S1 on the first convex lens 102 side. Therefore, the focal distance S1 distance on the first convex lens 102 side and the focal distance S2 on the second convex lens 103 side can be made different, and the pitch between the photoelectric elements 13 and 13 arranged in parallel, or each optical transmission path. Regardless of the pitch between 11 and 11, the photoelectric element group 12 or the optical waveguide group 12 can be connected by aligning the optical axis with the plurality of photoelectric elements 13 or the plurality of optical transmission paths 11 respectively.

  In the optical module described above, in order to transmit and / or receive optical signals in four channels, the optical waveguide group 12 has four optical transmission lines arranged in a row, that is, four in a one-dimensional array. And the photoelectric element group 14 also includes four photoelectric elements arranged one-dimensionally. However, the optical transmission line 11 and the photoelectric element 13 may be two-dimensionally arranged.

  For example, as shown in FIG. 13, as a photoelectric element group, PDs including a pair of light receiving portions (light receiving regions) 112 and electric wire portions 113 connected to the light receiving portions 112 are arranged in a row on a base material 111. In addition to the four-dimensional one-dimensional array of photoelectric elements 110, as shown in FIG. 14, a set of PDs is used as a two-dimensional array of photoelectric elements 114 arranged in 4 × 4. Also good.

It is a top view which shows the optical module of suitable 1st Embodiment. It is a top view which shows the optical module of suitable 2nd Embodiment. It is a see-through | perspective perspective view which shows the lens component of the optical module of suitable 3rd Embodiment. It is a plane which shows the modification of the lens component of FIG. It is sectional drawing which shows the connection structure of the lens component of FIG. 4, and an optical connector. (A) is a perspective view showing details of a lens component of an optical module according to a preferred fourth embodiment, and (b) is a top view of the lens component of (a). It is a top view which shows the optical module of 4th Embodiment. It is a see-through | perspective perspective view which shows the lens component of the optical module of suitable 5th Embodiment. (A) is a perspective view which shows the optical module of 5th Embodiment, (b) is a back perspective view of the optical module of (a), (c) is the optical module of (a). (D) is a side view of the optical module of (a). It is a figure which shows CAN type | mold PD, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows a ceramic package. It is a top view which shows the modification of the lens component of the optical module of 1st-5th embodiment. It is a perspective view which shows the example of a photoelectric element group. It is a perspective view which shows the other example of a photoelectric element group. It is a schematic diagram which shows the conventional optical module. It is a schematic diagram which shows the conventional lens component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical module 11 Optical transmission line 12 Optical waveguide group 13 Photoelectric element 14 Photoelectric element group 15 Lens component 16 1st convex lens 17 2nd convex lens 31 Lens block 64 Mirror L1-L4 Optical signal

Claims (12)

An optical waveguide group having a plurality of optical transmission lines, and a photoelectric element having a plurality of photoelectric elements for receiving optical signals from the respective optical transmission lines of the optical waveguide group or transmitting optical signals to the respective optical transmission lines Group, and between the photoelectric element group and the optical waveguide group, each of the optical transmission lines of the waveguide body group and the photoelectric elements of the photoelectric element group individually transmit optical signals or In an optical module including a lens component for receiving,
The lens component is disposed opposite to the optical waveguide group and has a first convex lens having an effective diameter larger than the distance between the optical axes of two optical transmission lines farthest from each other among the optical waveguide groups, A second convex lens disposed opposite to the photoelectric element group and having an effective diameter larger than the distance between the optical axes of the two photoelectric elements farthest from each other among the photoelectric element groups, wherein the first convex lens is an optical waveguide. The second convex lens is formed so that the optical signal from each optical transmission path of the body group is made into parallel light, or the optical signal that has passed through the lens component is condensed on each optical transmission path. The optical signal from each of the photoelectric elements is made to be parallel light, or the optical signal that has passed through the lens component is condensed to each photoelectric element, and the parallel light of each optical signal that passes through the lens component Formed so that the Light module according to claim.   The optical module according to claim 1, wherein the lens component is formed in a columnar shape, a first convex lens is formed at one end of the columnar body, and a second convex lens is formed at the other end.   The lens component is formed of a substantially rectangular parallelepiped lens block, the first convex lens is formed on one side of the lens block, and the second convex lens is formed on a side facing the side on which the first convex lens is formed. Item 4. The optical module according to Item 1.   The lens component is formed of a substantially rectangular parallelepiped lens block, the first convex lens is formed on one side of the lens block, the second convex lens is formed on the side of the lens block orthogonal to the side on which the first convex lens is formed, The optical module according to claim 1, wherein a mirror that couples the optical axis of the first convex lens and the optical axis of the second lens is formed in the lens block.   The lens block is formed in a substantially rectangular parallelepiped, a pair of first convex lenses is formed on one side of the rectangular parallelepiped, a second convex lens is formed on a side of the first convex lens facing the rectangular parallelepiped side, and the other first The optical module according to claim 1, wherein the other second convex lens is formed on a rectangular parallelepiped side orthogonal to the one convex lens, and a mirror is formed therebetween.   6. The optical module according to claim 4, wherein a hollow hole for forming the mirror is formed in the lens block at a position where the optical axis of the first convex lens and the optical axis of the second convex lens are coupled.   The lens component is formed of a substantially rectangular parallelepiped lens block made of the same material as that forming the first convex lens and the second convex lens, and a concave portion having substantially the same aperture as the first convex lens is formed on one side thereof. The first convex lens is formed in the concave portion, the concave portion having substantially the same aperture as the second convex lens is formed on the other side surface of the lens block, and the second convex lens is formed in the concave portion. Light module.   On the surface of the lens block on which the first convex lens or the second convex lens is formed, a fitting protrusion or a fitting groove for positioning and fitting with an external component such as an optical connector is formed. The optical module according to claim 3, wherein the focal point of the second convex lens is formed at a depth positioned on the opening surface of the concave portion.   The optical module according to claim 1, wherein a focal length of the first convex lens is different from a focal length of the second convex lens.   The optical module according to claim 1, wherein the optical waveguide group is a plurality of optical fibers that are one-dimensionally arrayed or two-dimensionally arrayed.   The optical module according to claim 1, wherein the photoelectric element group is a plurality of light receiving elements or light emitting elements arranged one-dimensionally or two-dimensionally.   12. The photoelectric element group according to claim 11, wherein the photoelectric element group is provided on a substrate, a cap having an optically transparent window formed above the photoelectric element group is fixed to the substrate, and the photoelectric element group is hermetically sealed. Optical module.

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